Air cleaner



Jan. 16, 1945. .w, w, LOWTHER" 2,367,227

AIR CLEANER Fi1e d May 2, 1942 Patented Jan-16, 1945 UNITED sfrATEs PATENT OFFlCE A182,367,227 R I Wilfred W. Lowtlier, Minneapolis, Application May 2, 1942, Serial No. 441,483

and which are often referred to in the art as the liquid washed type of air cleaner; More particularly, however, my present invention relates to improvements in air cleaners oi'the general type defined and which improvements are. directed particularly toward adapting this type of cleaner to types or service where they are apt to be operated at various'angles with respect to their normal right side up vertical positions.

Air cleaners oi the type containing a tree moving body of liquid have long been considered the most efllcient and desirable type for use in connection with internal combustion engines for removing dust from the air intakes thereof, but cleaners of this type have largely been avoided for use in connection with motorcycles and airplanes which frequently operate at severe angles with respect to their normal right side up vertical positions because of the generally recognized tendency of such cleaners to spill and lose oil under such conditions, and while some attempts have hitherto been made to provide air cleaners of this type, which would retain their oil under such conditions, such prior attempts have usually 1 Claim. (CL

my present invention relates The cleaners casing or shell is in the'nature of I a vertically disposed cylindrical section I that is closed at its upper end but which is primarily open at its lower end. The lower end of the caiiing section I is primarily open but is normally closed by a cylindrical oil sump-forming section 2 that is telescoped on to the lower end oi the section I. v

Opening axially through the bottom of the sump-forming section 2 is a vertically disposed intake tube 3 that rises to a level somewhat above the normal static liquid level in the well; the nor.

- mal liquid level being indicated by an annular bead I, and the liquid being indicated by 11. The lower end of the intake tube 3 is anchored to an annular flange 5 on the bottom of the sumptorming element 2 to provide a liquid tight Joint.

Disposed concentrically over the upper discharge end of the inlet tube 3 is an air stream direction reversing baille 8 preferably in the naresulted in increased cost, reduced efilciency and reduced air handling ability for a cleaner of given dimensions. Furthermore, such prior attempts to solve this problem have not been entirely-satisfactory with respect to their ability to retain their.

oil under all conditions of operation in connection with airplanes and motorcycles; it being understood that airplanes occasionally fly upside down as well as at severe angles to their normal ture of an inverted cup or the intake tube 3. This inverted cup-like baiile 8 has its top and its cylindrical sides spaced from the inlet tube 3, and receives the upper end por- 80 tion of said intake tube 3 to provide with said right side up positions and that motorcycles not 5 only operate at severe angles frequently but occasionally fall over on to their sides.

The air cleaner of my present invention is adapted to contain a suillciently large volume of liquid to permit operation under severe dust conditions for relatively long periods between servicing intervals; is highly eflicient in its air cleaning action; is capable of handling alarge volume of air-as compared to other cleaners of similar physical dimensions; will operate satisfactorily throughout a wide range of angles with respect tube a downwardly directed annular continuation of the air intake passage through said tube 3. The cup-like baille 6 is integrally formed with an annular coupling flange I with which it is connected by means of a spider consisting of circumferentially spaced series of narrow spokes 8, which latter are not shown in detail but of which there may be assumed to be four or six. The spokes 8 to its normal right side up vertical position; and

can be operated at all' rotated positions with respect to its normal right side up position, including an upside down position, without serious loss of oil through its inlet, outlet or otherwise.

The above and other highly important objects and advantages of the invention will be made of the spider, being very few in number and very narrow, will, of course, provide no substantial reduction in open area between the lower edge oi the inverted cup 6 and the side of the casing.

The, coupling flange 1 is loosely-telescoped over the lower end of the shell section I and isprovided with an outturned cross-sectionally channel shaped flange 9 at its upper end that nests under a similarly shaped flange Ill on the sectional The sump-forming section 2 of the'casing is, turn, loosely telescopically applied over the flange I and is provided with a beaded upper edge II that is nested under the channel shaped flange 9. The flanges 9, l0 and II are normally detachably held together by a split channelshaped clamping ring or' band l2.

Leading from the upper portion of the cleaner larger diameter than 4 c sing is a. clean air outlet tube or conduit is, the receiving end of which tube or conduit it is downwardly directed and co-axially aligned with the air intake tube 3, baflle i and the cylindrical walls of the casing. While in some instances it may be desirable to have this clean air outlet tube It extend vertically axially throu h the top of the casing, the present disclosure shows this tube as being in the nature of an elbow extending outwardly through the upper side portion or the casing whereto it is rigidly anchored, by welding or the like, to a casing flange it. The receiving end of the clean air outlet tube It is well spaced tromthetoporbailielandtheentineapace within the cleaner casing between the open lower end oi mile 0 and the receiving end oi ,the outlet to the tube is well below resectio -amuse t and is directed radially outwardly and upwardly from said tube 3.

, providebetween-saidfiange II of the baiile 8 and thebaillellanupwardlydirectedannularair passage ll oi considerably greater cross-sectional area;tban-tbe cross-sectional area oi the annular '10 passage between the cylindrical wall oi baflle t tube It constitutes an air expansion chamber and is preferably filled with an air pervious liquid collecting element which, as sham comprises a plurality of stacked corrugated woven wire screens II and II. Those screens II which surround the bai'ile B may be assumed to be like those 01! the Schulz Patent No. 2,011,303 0! AW 13,

1935, whereas the screens II above the baiile l are formed to provide straight parallel corrugations and stacked so that the corrugations of ad- ,iacent screens extend transversely one to the other: to prevent nesting.

The screens It and II are stacked one upon I the other and the whole supported upon radial annular flanges i1 and I1 and the spokes lot the spider and are held against upward displacement by virtue of engagement with the receiving end v is readily removable for servicing when. the

clamping band It is loosened or removed, and when the sump is thus removed the baiile I and integrally formed spider and flange I may be readily removed which will permit the screen elements to be likewise displaced for such servicing as may be necessary.

It may be stated, however, that the intercepting and oil collecting element made up of the screens I5-II' is not a filter in the sense that tightly packed metal shavings, moss, fiber or horse hair constitute a filter and is not usually subject to clogging with dust; its function being to intercept and return liquid to the sump rather than to filter out dust.

It is important to note that the cleaner-is so designed that the fluid level. will be safely spaced from the open inner ends of the intake tube I and outlet tube I3 under all rotated positions of the cleaner. For example, when th cleaner is turned on its side by rotating the same 90 in a counterclockwise direction with respect to the drawing, the fluid level would be indicated by a broken line d-a, and if the cleaner b turned 180 to an upside down position, the fluid level will then be indicated by broken line b -b. By reference to the drawing it will be noted that lines H and b-b are safely spaced from the open inner ends of the tubes 3 and I! so that no oil will escape through either thereof under these conditions.

Preferably the structure further includes a cuplike baille element It that is applied concentrically over and anchored to the intake tube 3 by welding or the like. This ballie II is anchored iil'tlkd'tubc 3. It is important to note,

however, that the maximum diameter oi baille II is considerably less than that oi the interior or the casing. The baille II is, preferably and as shown, located substantially wholly within the oil sump and is preferably provided with small liquid fiow passages II for communication between the interior of hello I. and that portion oi the liquid sump outwardly of baiile ll.

- Operation.

Assuming now that the projected end of clean air outlet tube I: of the cleaner is connected to the intake of an internal combustion engine in the usual manner and that saidengine is operating, the cleaner will function substantially as follows.

Partial vacuum will be produced in the engine's mtake as a result of the engine pistonintake strokes, and air will rush into the engine's intake through the cleaner under atmospheric pressure.

Atmospheric air will enter and pass through the axial air inlet tube 3 at high velocity and will discharge into the inverted cup-like balls I within which the direction oi the air will be reversed and passed downwardly into the inner cup-like battle it. Upon entering the cup-like baille i8,

the annular stream of air will again reverse its direction of travel and will pass upwardly through the annular air passage it into the screenq i ped expansion chamber from which the air will, of course, pass outwardly through the clean air outlet tube It into the engine. Oil or other fluid that normally largely fills the baflle ll under static conditions will be largely displaced therefrom and carried upwardly into the screenequipped expansion chamber with the incoming air initially introduced. That is, most of this oil will be picked up by the air and delivered into the screen-equipped expansion chamber. This oil thusly carried up into th expansion chamber will form films over the openings in the several lower screen elements I! only to be broken and formed over other screen openings while draining downwardly back to the liquid sump, the screens serving largely as a liquid intercepting and returning medium. 0! course, the air stream passing above the upper edge of baille I6 and into th expansion chamber will expand rapidly at this point andthe velocit of the air will be greatly reduced within the expansion chamber.

A large portion of the oil displaced from the cup-like bafile It will accumulate and build up a head of oil radially outwardly oi the upper edge of baifle' l8 and this head. of oil will constantly tend to overflow the upper edge oi bail'le II and will be picked up by the expanding air stream only to become mixed with the air and then ultimately returned by the screens to this head By the time the air has,

Due partly to the fact pands within part to the fact that there is of oil above the oil passages Hi, there will be an inward flow of oil through these passages l9 under operating conditions which will further tendto keep the expanded air stream supplied with oil.

A large part of heavier' particles the air through the dust, and in fact all of the of dust, will be removed from the process of impingement within the lower part of the cup-lik baifle l6,

and the balance of the dust, consisting mostly oithe lighter ends, will become dust coated during its passage through the cup-like'baflle l6 or within the lower portions of the expansion chamber, and such dust will be trapped in the oil and thereof, said air intake tube upwardly terminating with its upper end above the maximum nor 'mal static liquid level in said sump, and inverted cup of greater diameter than said air intake tube the open upper end of said intake tube with its closed top and its sides spaced from the upper end portion of the said intake tube, whereby to' provide with said air intake 1 tube a downwardly directed annular continuedelivered to the bottom of the oil sump where it will be collected.

Not only does the cleaner described operate very efiiciently at a wide variety of angles'with respect to its normal vertical position, but it will permit uninterrupted engine operation and will retain its oil in all rotatedpositions including an upside down position such as is encountered frev quently' in airplane use. Furthermore, the constructionillustrated is simple and inexpensive, is

easily serviced, and has a relatively very great air handling ability with respect to its overall physical dimensions.

What I claim is:

In an air cleaner of the liquid washed type, a vertically disposed casing closed at its upper and lower ends and providing a normal liquid sump in its bottom, a vertically disposed air intake tube concentrically disposed with respectto the sides of the casing and opening through the bottom diameter than tion of the upwardly directed air passage formed by said intake tube, an air outlet conduit opening through the upper portion of the casing and terminating with its air inletend disposed coaxially of the casing and downwardly directed and in axially spaced relation to the closed upper end of said inverted cup, an air pervious liquid collecting medium filling thespace within the casing between the lower edge of the inverted cup and the intake end of the outlet conduit, the closed upper end of the casing providing an emergency sump above the medium surrounding the outlet conduit so as to receive the-entire oil supply from said normal sump when the casing is inverted, and an annular cup-like baffle'concentrically disposed around the air intake tube within the normal liquid sump, the upper edge of said cup-like baille terminating in close proximity to the plane of the lower edge of the inverted cup and being of greater diameter than said lower edge of the inverted cup but of materially less the interior of the casing, whereby to provide an annular upwardly directed continuation of the downwardly directed passage portion formed by the intake tube and the inverted cup and an annular liquid return passageto the sump surrounding said cup-like baflle.

- WILFRED W. LOWTHER. 

